Skeleton keys

Chimpanzee bones may be evolutionary gold mine, relatively speaking

Kinship between humans and other animals was already a subject of interest in 1857 — two years before Charles Darwin published “On the Origins of Species.” Here, photographer Charles Dodgson (better known as Lewis Carroll, author of “Alice in Wonderland”) photographed a friend, Reginald Southey, with skeletons of a human and other primates. The image is part of the "Endless Forms: Charles Darwin, Natural Science and the Visual Arts" exhibit at the Fitzwilliam Museum, University of Cambridge. (National Media Museum, Bradford UK)

Kinship between humans and other animals was already a subject of interest in 1857 — two years before Charles Darwin published “On the Origins of Species.” Here, photographer Charles Dodgson (better known as Lewis Carroll, author of “Alice in Wonderland”) photographed a friend, Reginald Southey, with skeletons of a human and other primates. The image is part of the "Endless Forms: Charles Darwin, Natural Science and the Visual Arts" exhibit at the Fitzwilliam Museum, University of Cambridge. (National Media Museum, Bradford UK)

Sixth in an occasional series of features marking the 200th anniversary of Charles Darwin's birth (Feb. 12, 1809) and the 150th anniversary of his landmark book about evolution and natural selection, “On the Origin of Species.”

If scientists ever fully trace the evolutionary path of people, some of the answers may come from a group of 30 or so chimpanzees who lived and died in Arizona, then came to San Diego.

The Center for Academic Research and Training in Anthropogeny (CARTA) at the University of California San Diego has begun digitizing dozens of skeletons of apes who once resided at the Primate Foundation of Arizona (PFA), a nonprofit organization in Mesa, Ariz., that took in, cared for and studied unwanted chimpanzees for more than 30 years.

The skeleton collection is the first tangible component of CARTA, a novel and largely virtual institute established last year to encourage a deeper, multidisciplinary study of human origins. Though CARTA has offices at UCSD and the nearby Salk Institute, most of its diverse worldwide membership, which ranges from anthropologists to medical doctors, biochemists and neuroscientists, is connected via the Internet and a common curiosity about how man began.

“The question of human origin is not something that can or will be solved by any single field of science. Finding answers requires cooperation,” said Dr. Ajit Varki, a physician and professor of cellular and molecular medicine at UCSD who co-directs CARTA.

“There's only one place in Germany – the Max-Planck Institute for Evolutionary Anthropology – that sort of tries to do this, but that's not enough. We need to expand and deepen the effort.”

The chimpanzee skeletons, which were donated to UCSD because the PFA is closing down, are a major first step by CARTA in that direction and something of a scientific windfall. Collections of chimpanzee skeletons are rare. Even rarer, however, are skeletons with well-documented histories. These chimpanzee skeletons from PFA come with extensive medical records attached, from radiographs and old blood samples to years of observation logs chronicling their owners' lives.

“It's a huge amount of material, which we can sort through for all kinds of information,” said Varki. “For example, we can look at a chimp's routine blood tests over the years. We can see how its blood values changed with age and if there was any corresponding impact on the bones.”

More profoundly, the ape data could help illuminate human origins and development, said Margaret Schoeninger, a biological anthropologist at UCSD and CARTA co-director. “One of the things that jumps out at me is the possibility of doing some really detailed biomechanical studies of the skeletons, looking at the shapes of chimpanzee bones related to locomotion and seeing how they differ at a fine level from humans.”

(Schoeninger said CARTA is also attempting to acquire an extensive collection of macaque skeletons, which would give them a monkey database to compare with chimps and humans.)